Chapter 4 - Integumentary System Flashcards
Two layers of the dermis layer
- Papillary layer
2. Reticular layer
Anchors the epidermis and nourishes it
Dermal papillae
Three components to the papillary layer
- Areolar CT
- Capillaries and neurons
- Dermal papillae
Job of the reticular layer of the dermis
Anchoring layer
What does the reticular layer contain in the dermis?
Large vessels, nerves, adipocytes, arrector pili muscle
What kind of tissue is in the reticular layer of the dermis?
Dense irregular CT (Collagen and elastic)
- In subcutaneous layer
- Network of arteries and veins supplying skin
Cutaneous Plexus
- Follows epidermal and dermal boundary
- Helps nourish epidermal layer
Papillary Plexus
How do stretch marks form?
- Weight gain causes fibers to stretch; they lose elasticity and break
- decrease in fiber elasticity
- tearing of fibers
What is the subcutaneous layer composed of and what are its functions?
- Areolar CT and adipose CT
- Collagen and elastic fibers
- No distinct boundary with dermis
- Major blood vessels and nerves
- Stabilizes skin
Where is there no hair?
- Plantar/palmar regions
- Digits
- Eyelids
- Lip
Three types of hair and meanings
- Vellus - peach fuzz
- Intermediate - arms
- Terminal - thicker with darker pigment
Mostly projects above the surface of the skin
Shaft
Penetrates into the dermis
Root
Base of the follicle
Bulb
Each hair is composed of these three layers (outside to inside)
- Cuticle
- Cortex
- Medulla
Surrounds the root of a hair
- Has many sheaths and layers
Hair follicle
Hair is composed of _________________ epidermal cells
Dead, keratinized
Functions of hair
- Protection
- Reduction of heat loss
- Sensing light touch
- Sensory nerves surrounding follicle
- Detect hair movement
Root hair plexus
- Smooth muscles
- Moves hair
- Goose bumps
Arrector Pili
Three stages to hair growth
- Anagen stage
- Catagen stage
- Telogen stage